Corporate Check Stock (Blanks)

Hi Fellow Auditors, I'm a little perplexed with control over our new corporate check stock reserve supply which we had to reorder for our new core computer system (Open Solutions Inc).  I call it "stock" because the only pre-print is our ABA number and CU name and address; other security features of microprint and watermark are still included.  The unissued checks are not serial numbered or MICR encoded, which is now a part of the issuance process. The working supply is maintained in a single-custody locked printer during the day and only checks issued are verified each night.  With this type of blank check stock, what internal controls do we need for  unissued checks?  I'm having a hard time thinking about, and what would support, requiring dual control for the blanks overnight.Any ideas would be greatly apprciated....Thank you,Sue